The invention relates to an air-conditioning system for an air-cooled motor vehicle of the type having a housing in which an evaporator, a chamber and at least one fan are arranged, the housing having outflow ducts with individually blockable defroster nozzles, center nozzles and leg area nozzles, through which heated air and/or cold air can selectively be introduced into the vehicle interior, the housing being connected with at least one heated-air duct containing an exhaust heat exchanger as well as with inflow ducts for fresh air and circulating air.
In a known air-conditioning system of the initially mentioned type described in German Published Unexamined patent application (DE-OS) No. 32 17 825, the housing is provided with a mixing chamber, at least one inflow duct for heated air, one inflow duct for fresh air and one inflow duct for cooled air leading into this mixing chamber. In the mixing chamber, an adjustable partition is provided which considerably influences the distribution of the entering air flows to the outlet ducts. The arrangement of the partitions results in a thermal stratification. This arrangement has the disadvantage that the considerably fluctuating heated air temperatures which occur particularly in an air-cooled vehicle as well as the fluctuations of volume are very difficult to compensate.
It is an object of the invention to take such measures at an air-conditioning system for a preferably air-cooled vehicle that the varying heated-air temperatures as well as the volume fluctuations can be compensated rapidly so that a uniform temperature exists in the vehicle interior.
According to the invention, this object is achieved by providing an arrangement, wherein heated air and/or fresh air and/or circulating air or cooled air is jointly introduced into at least one fan and is swirled together and mixed in this fan, and wherein the mixed air is guided subsequently by way of individual outflow ducts to the vehicle interior, and wherein a blow-out sensor is arranged behind the fan for scanning the temperature deviation (.DELTA.T) of the mixed air from the adjusted desired temperature and, as a function of the temperature deviation (.DELTA.T), automatically correcting the position of a temperature mixing flap provided in front of the fan.
Principal advantages achieved by the invention are that, by means of the swirling-together and mixing of the individual air flows (heated air, fresh air, circulating air, cooled air) in the fan wheel of the fan and the automatic connecting of the temperature mixing flap, a largely constant temperature is achieved in the vehicle interior. The occurring fluctuations of the temperature and of the volume of the heated-air flow are therefore compensated rapidly. The differential-pressure-controlled flaps arranged in the heated-air duct behind the exhaust heat exchangers have the result that the hot air is blown off, if necessary, and air can also flow through the heat exchangers during the summer. When the temperature mixing flap closes the heated-air duct, the differential-pressure controlled flap opens automatically. By means of the arrangement according to the invention, mainly a fast response of the air-conditioning system is achieved to changing temperatures or volume fluctuations and an almost uniform air temperature at all outlet ducts.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.